dt-bindings: soc: tegra-pmc: Document core power domain

All NVIDIA Tegra SoCs have a core power domain where majority of hardware
blocks reside. Document the new core power domain properties.
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.yaml

@@ -301,6 +301,33 @@ patternProperties:
 
     additionalProperties: false
 
+  core-domain:
+    type: object
+    description: |
+      The vast majority of hardware blocks of Tegra SoC belong to a
+      Core power domain, which has a dedicated voltage rail that powers
+      the blocks.
+
+    properties:
+      operating-points-v2:
+        description:
+          Should contain level, voltages and opp-supported-hw property.
+          The supported-hw is a bitfield indicating SoC speedo or process
+          ID mask.
+
+      "#power-domain-cells":
+        const: 0
+
+    required:
+      - operating-points-v2
+      - "#power-domain-cells"
+
+    additionalProperties: false
+
+  core-supply:
+    description:
+      Phandle to voltage regulator connected to the SoC Core power rail.
+
 required:
   - compatible
   - reg
@@ -325,6 +352,7 @@ examples:
     tegra_pmc: pmc@7000e400 {
               compatible = "nvidia,tegra210-pmc";
               reg = <0x7000e400 0x400>;
+              core-supply = <&regulator>;
               clocks = <&tegra_car TEGRA210_CLK_PCLK>, <&clk32k_in>;
               clock-names = "pclk", "clk32k_in";
               #clock-cells = <1>;
@@ -338,17 +366,24 @@ examples:
               nvidia,core-power-req-active-high;
               nvidia,sys-clock-req-active-high;
 
+              pd_core: core-domain {
+                      operating-points-v2 = <&core_opp_table>;
+                      #power-domain-cells = <0>;
+              };
+
               powergates {
                     pd_audio: aud {
                             clocks = <&tegra_car TEGRA210_CLK_APE>,
                                      <&tegra_car TEGRA210_CLK_APB2APE>;
                             resets = <&tegra_car 198>;
+                            power-domains = <&pd_core>;
                             #power-domain-cells = <0>;
                     };
 
                     pd_xusbss: xusba {
                             clocks = <&tegra_car TEGRA210_CLK_XUSB_SS>;
                             resets = <&tegra_car TEGRA210_CLK_XUSB_SS>;
+                            power-domains = <&pd_core>;
                             #power-domain-cells = <0>;
                     };
               };